On 04-11-16, 10:57, Akshay Adiga wrote:
> Adding fast_switch which does light weight operation to
> set the desired pstate.
>
> Signed-off-by: Akshay Adiga <akshay.ad...@linux.vnet.ibm.com>
> ---
> drivers/cpufreq/powernv-cpufreq.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/powernv-cpufreq.c
> b/drivers/cpufreq/powernv-cpufreq.c
> index d3ffde8..09a0496 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -752,9 +752,12 @@ static int powernv_cpufreq_cpu_init(struct
> cpufreq_policy *policy)
> spin_lock_init(&gpstates->gpstate_lock);
> ret = cpufreq_table_validate_and_show(policy, powernv_freqs);
>
> - if (ret < 0)
> + if (ret < 0) {
> kfree(policy->driver_data);
> + return ret;
> + }
>
> + policy->fast_switch_possible = true;
> return ret;
> }
>
> @@ -897,6 +900,22 @@ static void powernv_cpufreq_stop_cpu(struct
> cpufreq_policy *policy)
> del_timer_sync(&gpstates->timer);
> }
>
> +static unsigned int powernv_fast_switch(struct cpufreq_policy *policy,
> + unsigned int target_freq)
> +{
> + int index;
> + struct powernv_smp_call_data freq_data;
> +
> + index = cpufreq_table_find_index_dl(policy, target_freq);
> + if (index < 0 || index >= powernv_pstate_info.nr_pstates)
> + return CPUFREQ_ENTRY_INVALID;
I don't think such a check is required at all. It wouldn't happen without a BUG
in kernel.
> + freq_data.pstate_id = powernv_freqs[index].driver_data;
> + freq_data.gpstate_id = powernv_freqs[index].driver_data;
> + set_pstate(&freq_data);
> +
> + return powernv_freqs[index].frequency;
> +}
> +
> static struct cpufreq_driver powernv_cpufreq_driver = {
> .name = "powernv-cpufreq",
> .flags = CPUFREQ_CONST_LOOPS,
> @@ -904,6 +923,7 @@ static struct cpufreq_driver powernv_cpufreq_driver = {
> .exit = powernv_cpufreq_cpu_exit,
> .verify = cpufreq_generic_frequency_table_verify,
> .target_index = powernv_cpufreq_target_index,
> + .fast_switch = powernv_fast_switch,
> .get = powernv_cpufreq_get,
> .stop_cpu = powernv_cpufreq_stop_cpu,
> .attr = powernv_cpu_freq_attr,
> --
> 2.7.4
--
viresh
